Comprehensive Description

Description

Occurrence. St. 42: South Georgia, 120-204 m.; St. 148: South Georgia, 132-148 m.; St. 156: South Georgia, 200-236 m.; St. WS 25: South Georgia, 18-27 M.

DIAGNOSIS. Sponge massive; surface hispid and produced into papillate processes or meandrine ridges which may be so strongly developed as to give a clathrate appearance, or may be reduced to a feeble furrowing; pores apparently small and simple, and scattered evenly throughout dermis; oscules circular, 1-2 mm. in diameter, with delicate membranous velum, leading into cavernous sub-dermal crypts; often there is a single deep cloaca with a number of smaller oscules scattered over surface generally; texture firm and slightly compressible; skeleton a dense or feebly knit reticulation of styli, often showing strongly marked primary fibres which project slightly beyond ectosome as surface brushes; auxiliary spicules, found chiefly associated with dermal brushes, slender sub­tylostyli; microscleres toxa and chelae; styli of main skeleton slightly curved, 0•36-0•51 by 0•013–0•028 mm.; auxiliary subtylostyli, straight with crown of spines at basal end and with distal end pointed or, occasionally, blunted and spined, 0•23–0•32 by 0•006 mm.; toxa of varying size, smaller forms slender and strongly bent, larger stout and strongly spined at ends, 0•03-0•54 mm. long; isochelae palmatae, 0•009–0•015 mm. chord.

REMARKS. The species is characterized by its external and by the character of the microscleres. In many respects it resembles Artemisina dianae, Topsent, and forms, in fact, a connecting link between the two genera Ophlitaspongiaand Artemisina, so that it becomes a matter of doubt whether these two genera can be maintained.”